In the NBA playoffs, No. 1 seeds have a special air of authority about them. Since the league expanded to a 16-team playoff format in 1984, top-seeded teams have won their conference about 55 percent of the time; unlike in sports that feature heavy randomness, it’s a surprise when the best team doesn’t win out in the NBA.But that doesn’t mean top seeds are invincible, as the Golden State Warriors found out Sunday night in Oklahoma when they lost 133-105.